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Hi guys,

now I bought a little mining rig with 3 Sapphire hd 7950 boost. The cards came today and at this moment we only have 2 cards running in a case. I live in Germany an have to pay $0.36-0.37 for one kilo watt. Now I found a way to get 650kh/s with each card but the power consumption is rather high. I read about people who only paid 5cents per kw/h, so that power consumption is not significant. Here in Germany the power costs are half of my earnings.

So I use the cgminer. I know, that theoretically matters are the parameters thread-concurrency, gpu-engine and gpu-memclock.

So what is the best way to find the sweet spot? From the 650kh/s solution, should I try all parameters at 75%, 80%, 85%, 90%, 95%? Or that with every parameter? Should I try just to turn down one of these parameters?

Any ideas?

Thanks you  :)

The only way to do it is to measure power draw at different hash rates and plug them into calculators. I find 600 kH/s to be a good compromise between performance and power use. I've gone as high as 670 kH/s on a 7950, but beyond 600 kH/s the power use really starts to increase rapidly.

I also don't max out my GPUs not because of power costs, but because I want to plug as many rigs into a single outlet as possible, without tripping the circuit breaker.

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Thanks. I'll try 600kh/s, but there are several configs which would archieve that, right? I could only put down the gpu-engine, or only thread-concurrency...?

Same card. I undervolt mine to save electricity

1.025V

core clock 1035
mem clock 1450

620khs

I'm curios, what is your effective power consumation by your rig?

What is the power output from the wall? And what are you using for your rig?

The card itself has been tested with 288 Watts (max-power, the rest of the system could be calculated out of it).

Star3Bit